As we have demonstrated in earlier work [1]}, [2]}, [3]}, [4]}, while the individual contributions to massive helicity-zero spin-2 scattering amplitudes do each grow like \({\cal O}(s^5)\)  in compactified gravity theories, cancellations occur between these contributions ultimately ensure the overall 2-to-2 scattering amplitudes grow no faster than \({\cal O}(s)\) .See also [5]}, [6]}. These cancellations require that the couplings and masses of the Kaluza-Klein spin-2 and spin-0 modes be constrained to satisfy various sum-rule relations, which we have shown to be satisfied in both flat and warped compactifications.
